5.4: Fingerprint Scenario
- Page ID
- 53017
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)One of your author’s favorite fingerprint development stories involved mutual aid to a neighboring city. The local police were experiencing a repeated crime involving a young man who was on State parole, wherein the parolee would stand on a corner near his residence and point a handgun at the motorists while shouting gang slogans. Upon hearing the sirens of responding police cars, the suspect would sprint back to his house and hide. After three days of this cat-and-mouse game, the local police formulated a plan to catch the culprit. They stationed marked and unmarked police vehicles strategically around the block. They also had officers hiding nearby on foot. When the suspect repeated his daily shenanigans, the officers were in quick pursuit. Unfortunately, the suspect was fleet-footed and ducked behind an abandoned vehicle parked in the driveway of his house. Officers arrived just as he locked and closed the door to the vehicle. The deputy chief of the agency arrived on scene, looked through the dirty front passenger door window, and saw what he believed to be the butt of a handgun protruding from under the driver’s seat. Therefore, the vehicle was seized as evidence, towed to the station, and a search warrant petitioned. Once the warrant was approved, the deputy chief called to see if your author was available to process the vehicle for the suspected handgun. Upon your author’s arrival, he photographed the vehicle in its entirety and worked his magic to unlock the locked door. He then went to his vehicle to prepare for the task of recovering the suspected handgun and collecting DNA evidence. As he did this, he noticed that four of the police officers, along with one sergeant, had gathered in the parking lot. Not to his surprise, sadly, he observed the sergeant don a pair of gloves, and advanced one step towards the suspect vehicle. Your author knew that he would have to stop them from contaminating the evidence, but before he had a chance to move, the deputy chief appeared and scolded them most harshly. “But D.C., we just want to see if the gun is stolen.” Knowing this, your author cut a sheet of clean butcher’s paper and laid it on the front footwell of the vehicle. He carefully moved the gun onto the shiny side of the paper, and photographed the serial number, which he provided to the gathered curious personnel. Vindicated that the gun was indeed stolen, they retreated into the station, and your author was left to finish processing the gun. Carefully, your author swabbed the gun for touch-DNA, and then gently removed the stainless-steel magazine. It was then that he observed the glistening inherent luminescence of a left thumb print, in fact, the suspect’s left thumb print. No development was needed, as the print was patent. Your author is confident, had the sergeant manipulated the handgun to “render it safe” or to copy the serial number, the thumb print may not have survived. As it was, the print was enough to send the suspect back to prison for three additional years.
